Photographic treating bath



Patented Apr. 25, 1939 UNITED STATES PHOTOGRAPHIO TREATING BATH Georg L. Maiser, Dessau, Germany, asaignor to Agfa Ansco Corporation, Binghamton, N. Y., a corporation of New York No Drawing. Application April a, 193i, Serial 4 Claims.

My invention relates to photographic treating baths and more particularly to the protection of such baths from putrefaction.

An object of my invention is to prepare a photographic treating bath resistant to putrefaction by the addition of an acridine derivative amidated at the meso-carbon atom. Another object are the treating solutions containing said acridine derivatives. Further objects will be seen from the detailed specification following hereafter.

Photographic developers, intermediate washing baths and other photographic solutions which have been used for a long time develop, particularly in the warm'months, an evil smell due to the putrefaction of the gelatine, paper and glue particles which they contain.

This odor is not only a burden to the worker in the dark room, but also diminishes the permanence of the developer, since by the decomposition process the developer as such is prematurely destroyed. V

For avoiding this trouble it has been proposed to add to the, tank developer in which the development of odor is most frequent on account of the heavy use "and long retention of this developer a disinfectant, for example phenol, thym'ol, a fluoride or a mercury salt. Such additions may prevent the foul odor, but do not avoid the destruction of the developing properties by the putrefying process. The said additions have also the disadvantage that they either give rise to fog or depress the gradation or the initial sensitivity which can be produced by the developer.

This invention is based on the observation that the acridine derivatives amidated at the mesocarbon atom which are known disinfectants are surprisingly good agents for preventing putrefaction in photographic developers. By the addition of these substances to developers and other photographic baths all the aforesaid disadvantages attending. the addition of disinfectants are avoided.

The manufacture of 9 amino-acridines is described in the United States Letters Patents 1,-

629,873, 1,889,704 and 1,766,403.

The addition of 0.04'to 0.1 per mille of an acridine amidated at the meso-carbon atom to a tank developer prevents the production of any putrefaction notwithstanding that the developer may be in constant use under tropical conditions; the

In Germany April 11, 1936 developer contains its permanence and efiiciency until the complete exhaustion of the developing substance; in a comparison it is found that the developer containing the acridine derivative does not putrefy even after 2 months, whereas the same developer without the addition is useless after 2 weeks owing to putrefaction.

With the hitherto known disinfectants for this purpose a developer may remain odorless up to two months, but long before this limit a considerable depreciation in its developing properties can be detected; inparticular it will no longer completely develop the photographic layers, since the originally developed gradation can no longer be attained and the initial sensitivity is not wholly developed.

The specific favorable effect of 9-aminoacri- Y dine is the more surprising because other like acridine derivatives, for example 9-phenylacridine, 3 :fi-diamino-IO-methylacridiniuni chloride, 3z6-dimethyl 10-methylacridinium chloride have either no efiect in preventing the putrefaction of trough developers or detract from the developing properties of the developer in manner quite similar to the effect of hitherto used disinfectants.

The following examples illustrate the invention:

Example 1.---To litres of a trough developer there are added 2 to 7 grams of Q-aminoacridine. The developer is thereby protected from the action of putrefaction bacteria even at high temperatures until it has been completely exhausted, which with favorable composition of the developer does'not happen before the lapse of 2 months.

Example 2.The developer is prepared by the following recipe:

' Grams Para-methylaminophenol sulfate.-.. 1 Hydroquinone 2 Anhydrous sodium sulfite 25 Anhydrous sodium carbonate l 4 1 Potassium bromide 1 Q-aminoacridlne 0.1

This developer is dissolved in the usual manner in 1000 cc. of water and resists the action of putrefaction bacteria.

Applicant wishes to state that his invention is not limited to the specific examples given, but other photographic material may be protected pie a bath for inten'upting the development or a fixing bath. In like manner other a cridine derivatives amidated at the meso-carbon'atom, for

example 2-eth0xy-6:9-diam1no-acridine or 2- methoxy-6-chloro-9-(diethylaminopentyl) aminoacridine may be used. c

Applicant may use for instance Q-aminoacridine:

' 2-ethoxy-6 Q-diamind-acridlne:

aminoacridine:

. CIHI CH CH CHrCHFCHPI/ I I 2,155,501 "from the phenomena of putrei'action, for 'exam- What I claim is:

1. A bath comprising an aqueous solution ot-a photographic treating agent and a stabilizing agent consisting of an acridine derivative corresponding to the following general formula:

sisting of NH1 and if being a member selected from the group consisting of OCH3, OCaI-Ia, and H. Z being a member selected from the group consisting of H, NH:,

among L. m 

